A general slide fastener includes a pair of left and right fastener stringers where a plurality of zipper teeth is attached along edges of a pair of left and right fastener tapes facing each other. An upper stop is fixed to one end of a zipper teeth row of the fastener stringer, a lower stop is fixed to the other end thereof, and the zipper teeth rows are inserted into a slider that opens and closes left and right fastener stringers. In general, the slider opens and closes the left and right fastener stringers by being slid along the zipper teeth rows.
There is also known a so-called quick open-type slide fastener that can quickly disengage closed left and right fastener stringers without the sliding of a slider unlike the general slide fastener. In a slide fastener proposed in, for example, Japanese Patent No. 4103088 (Patent Document 1), a slider is divided into two pieces, that is, left and right components and the left and right component are adapted to be capable of being engaged with and disengaged from each other by circular magnets for the purpose of the easy opening of the left and right fastener stringers in a left-right direction.
Further, in a quick open-type slide fastener disclosed in the specification of U.S. Pat. No. 2,575,501 (Patent Document 2), a predetermined number of zipper teeth, which are disposed at the end portion of a zipper teeth row of one fastener stringer corresponding to an upper stop, are excluded and a gap of a tape insertion passage is set to be larger than a general gap so that a portion of a fastener tape where the zipper teeth are excluded is easily separated from the tape insertion passage formed between upper and lower flanges of upper and lower wing pieces of a slider. The reason for this is to prevent a core portion attached to the fastener tape from being caught by the tape insertion passage formed between the upper and lower flanges of the upper and lower wing pieces of the slider in the case of the general gap.
When intending to forcibly disengage the quick open-type slide fastener disclosed in Patent Document 2, a user applies lateral pulling forces to left and right fastener stringers after sliding the slider to the portion where the zipper teeth are excluded. Accordingly, while the slider remains on the other fastener stringer where zipper teeth are not excluded, it is possible to separate the core portion of the fastener tape, where the zipper teeth are excluded, from the slider through a tape insertion passage. Then, it is possible to release the engagement of the zipper teeth row in one stroke. The height of one flange of left and right flange of an upper or lower wing piece of the slider is made low, so that a gap of the tape insertion passage is increased by a constant width.